Jun 26, 2010

I love animation that shows us something we recognize, and we all recognize imperfection.

I wanted to do a post on how it can be really great to add imperfection to your animation, and in this case specifically how sometimes things like a perfect ease-in or overshoot can add an element of falseness to your work when creating animation in a certain style. I say this because I was watching the shots of a particular animator here at DreamWorks who does a wonderful job of this, and wanted to understand this a little more and include it more frequently in my own work.

When I used to animated in Maya, I was never a curve editor animator. I would just look at everything in the shotCamera, and track arcs in 3D using my motionTrail script. Here at work, the software we have for manipulating curves is so good, I quickly started doing a lot of stuff in the curve editor and making a habit of smoothing stuff out cleanly and watching to make sure that everything was easing in and out nicely.

I really love using the curve editor, and probably wouldn't go back to doing it all in the viewport, but I recently noticed that my movements were becoming too smooth, too calculated and my animation was losing some of that naturalistic punch that I used to see in my older stuff.

I usually go back to live action to figure out how things really move and how it relates to animation, and below I've shared a few videos that show examples of where we may be tempted to oversimplify and oversmooth the movement. In reality there is a lot of "imperfection" that we see in the arcs of movement without really realizing it, but its part of constructing our perception concerning whether or not something is real.

You can see immediately that the arc and the spacing on the foot is not what you might expect if you just started animating this from scratch...

The arc above shows how the curve might turn out based on our assumptions, and what were used to implementing. Its pretty "perfect" and quite different to how the real foot travels through the air.This would probably result in a semi-decent looking animation, but with something looking not quite right or as if not enough detail existed in the movement.

Instead of going nice and smoothly over the top of the arc, the foot drops slightly before it rises up again at the peak. This is the natural arc as the lower leg swings forward.

Theres an interesting section here where the foot slows down before it begins to fall. If you click back on the video, we see this as a slight pause in the leg, and it illustrates thought in the characters mind... a moment of calculation as his brain thinks about the best place to land the foot.

Notice how the foot doesn't fall to the final contact pose with that perfectly accelerating downward motion, its spacing is almost linear after it starts to fall, then suddenly accelerated just before the contact. The foot is not an object freefalling through space - the leg above it can alter and "imperfect" the spacing as it falls.

As the woman gestures, she holds out her hand, and for a part of the gesture she appears to hold it relatively still as she moves it screen right...

When we track this "smooth" part, its clear how irregular the arc is. Despite the fact its not obvious when we watch the video above, its all going on under the hood, and adding to our perceptions of whether or not the character is real.

The movements of the head are a particularly ideal place to use this idea. When we start animating, we quickly learn about what can make head moves appealing - such as dipping the nose on a turn, a slight nod or twist in the opposite direction before a change etc. These are by all means valid, and used wisely can really add to head animation. Take a look at some of these videos below where I tracked the nose to see how the head is moving, and you quickly see how "wobbly" and unsmooth the curves are. I find this stuff really interesting to study.

Here's another curve we might normally be tempted to smooth out - reducing its subtle realism. I love the little bump at the top, and the small "glitch" in the deceleration at the bottom of the curve.

The guy in the blue shirt above shows how erratic the arcs on a head can really be. Whether or not your shot would call for this kind of detail depends on many things, but its just really interesting to me to see how crazy it can get, on a move that isn't really that extreme at all.

Without getting into the subject of overlap and inherited motion, you can see clearly how a more complex action like sitting down and adjusting weight and balance can increase the scale of these direction changes.

Even movements that are supposed to appear smooth and elegant may contain these irregularities, they are just smaller and less noticeable.

The arcs are almost "smooth" but not quite. I might be tempted to round out the tops of the curves and even out the spacing, but these subtle effects can increase the believability.

As far as how to implement these irregularities, it is definitely something I would recommend doing right at the last stages of polish. You can do this by just playing with the curves and adding little bumps and notches, but it can be very hard to get it to look right, and not like you just screwed up smoothing your shot...The reason for calling this post "perfect imperfections" is because nature will always do this exactly right! If your software supports it, I would even recommend doing this on another animation layer, that way its easy to experiment and scale things bigger and smaller without changing your main acting underneath.

Its important to mention that in animation we don't strive for "realism", we strive for communication of the idea. If the idea is ultra realism, then yes we animate as realistically as we can, but normally we are extracting the essence of movement and simplifying it to make the statement clear. So then, are all these imperfections necessary? no, I don't think they are absolutely needed, but they do add a layer of information to the idea you are communicating - audiences all know instinctively that natural motion is varied and irregular, and by including this in your animation you help make your characters appear more lifelike - which may make the audience more likely to believe what they have to say.

Great post and great examples. My personal pet peeve is walk cycles with perfect, smooth overlap on the wrists. If animators would stop reading Richard Williams and start watching people walk in real life, they'd see people's wrists move in so many different ways. Instead of a smooth overlap, often the wrist seems to come back and drop with weight, shaking around as it moves back with the forearm. It's a small touch, but I think it adds to the physicality and believability of the character -- not to mention, you can customize it in different ways to be character-specific.

Great breakdown! Thanks for posting so many references and tracking diagrams, they add so much. I've been struggling with similar scenarios dealing with cleaning tangents and making the in/outs look good in the GE, but at the cost of the on screen performance. I look forward to implementing more of this approach.

I would add that it's not enough just to observe and copy the imperfections-- you have to analyze them too, and try to understand why they're happening (like you did with the foot in the first example.) That way you'll know which irregularities are worth exaggerating, and which ones it might be better to neutralize. Also, the analysis part is just plain fun!

really interesting stuff...Imperfections are definatly hard to get right, most of the time they look like a mistake, but when you get a couple right, it totally adds to your animation, I agree. glad to see you posting again.

Awesome blog post as usual! Really interesting to read and see the examples of those imperfections. It was really great to see in detail the tracked foot on the first jump. Amazing how that arc was nothing at all as I expected. Good stuff.

Thank you for this excellent post! Very informative and thorough as always, I've missed reading your blog. :) I like your advice about adding imperfections on another layer so you can keep the main arcs intact should anything go wrong.

Might I ask which project you're on at Dreamworks, if you're allowed to say? I have a couple friends over there.

This is a great discussion starter because I'm sure there are two camps for this topic.

Personally, I think the point of animation is to communicate clearly, as you said at the end, so for most applications adding this kind of detail is unnecessary. But I think for examples like your first one, where it's used to show thought processes, then it can really add to the piece overall.

The other reason I like perfect arcs is for precisely the fact you've just proved: People don't move in perfect arcs at all, but animation is about doing things you can't do in real life, making it clear, and entertaining. Sometimes, especially in traditional animation, seeing good arcs is really beautiful. If too much of this was implemented, you would start to approach a rotoscoped or motion capture look.

These are some great examples, and a topic that hasn't been covered in much depth on the internet. I have done these sorts of experiments with my own reference footage. Thanks for sharing! :)

nice to see people are still reading my nonsense. I appreciate your interest and the time you take to leave comments.

Erica, I am just wrapping up on Megamind.. not sure whats next...

Cassidy, you make an incredibly valid point, something I overlooked in the post - it is crucial to try and understand WHY you might add variances to the curves - whether its inherited motion or the nuance of acting gesture, this would make it much easier than randomly scattering things in by chance.

Daniel C, thanks for your comments too man. I think animation is a lot about doing things you can't do in real life, but also often about things you can ( hehe ).. sometimes the best animations are not the ones that are so extreme and so far removed from reality, but the ones that provoke the emphatic response from the audience by illustrating something to them that they do in fact recognize from the real life around them. Having said that - I agree with you 100% that perfect arcs and spacing can be wonderful to watch where they are called for by the character or scenario.

Protodeep, it all depends on the show style and the director. All directors however are looking for the best communication of the idea in the shot - if its a broad comedy moment then probably not, if its a moment where a character needs to feel real and provoke a specific emotional response, then chances are that subtle nuance will be necessary to sell that successfully, and the director is likely to look for that in what you present.

Great post Cameron. I've been doing a lot of large creature stuff at work lately and have really found these subtle shifts and quirks add a lot of the necessary flavor it takes to sell something storming around with a lot of weight behind it.

Great stuff here, most of this I have never thought of. Almost like someone said, things move in arcs and I said, "ok". That was the end of the thought, but you have taken it further. The more I learn about animation, the more I realize how much I DON'T know. Thanks, great post!

Cameron,Its wonderful to see a new post. I feel as if most of my previous animation classes have attempted to drill overlap perfection and smooth arcs into my brain and it is great to hear otherwise. Some "perfect" animation examples look beautiful in how that animator masterfully polished the movements out and other "imperfect" work looks so realistic with its organic movement, complete with twitches, flicks, and bumps in the movement. I guess its all about what you are going for....

Great post. Thanks for all the detailed examples. Those don't look like quick work to make. In feature work, we can be very guilty of taking out all the pops and imperfections. I've been known to call out a fix on something only to have the animator explain that it was intentional, then I apologize and put it back. I like it when it's on purpose and that's where analysis like this comes in. It shows us what is really happening and allows us to make the choice to put it in or not. One of my favorite examples of this is how much feet flop, like in a jump - especially look at horse hooves in a run. So much going on there!

My only problem with some of these examples is the hand-held camera which introduces all types of perceived imperfections that may not absolutely be there. This is one of the "tricks" I see in a lot of inexperienced animation reels - add a camera move to cover up unpolished animation. Just an observation. Thanks again for the great post.

My take on it is that is that this brings to light the ever-present tension between reality and design. 100% design is usually bad, 100% random realism is also bad. I usually prefer a lot of design in the structure, with a good measure of randomness for texture in the details. Does that make sense?

Great post Cam,I am working on a shot where the character is tracking (with eyes,head and bit of shoulders) a dog as it moves (off screen) screen left. The results were always looking way smooth and just weren't working. I recorded footage of myself doing the same, but had not taken notice of the little details as I panned my head. This tute really made me pay attention, and helped out the shot too! Lifesaver :)